Disassembly and reassembly of a tar archive

Abstract

Mechanisms for disassembling and reassembling a tar archive are disclosed. A computing device accesses a tar archive comprising a file payload data segment and a plurality of non-payload data segments. The non-payload data segments in the tar archive are identified. The non-payload data segments are stored in a replay log structure. The file payload data segment of a file is identified in the tar archive, and file identification data identifying the file is stored in the replay log structure. The file payload data segment is not stored in the replay log structure.

What is claimed is: 
     
       1. A method for generating a replay log structure comprising:
 accessing, by a computing device comprising a processor, a tar archive comprising a file payload data segment and a plurality of non-payload data segments; 
 identifying the plurality of non-payload data segments in the tar archive; 
 storing the plurality of non-payload data segments in a replay log structure; 
 identifying the file payload data segment of a file in the tar archive; 
 storing file identification data identifying the file in the replay log structure, wherein the file payload data segment is not stored in the replay log structure; 
 generating a payload data validation value based on the file payload data segment of the file; 
 storing the payload data validation value in the replay log structure; and 
 generating a reassembled tar archive by:
 accessing the file payload data segment of the file based on the file identification data;
 sending the plurality of non-payload data segments from the replay log structure in a same sequence as the plurality of non-payload data segments are arranged in the replay log structure; and 
 sending the file payload data segment of the file in a same position with respect to the plurality of non-payload data segments as in the tar archive. 
 
 
 
     
     
       2. The method of  claim 1 , wherein the payload data validation value comprises a 64-bit cyclic redundancy check (CRC) value. 
     
     
       3. The method of  claim 1 , wherein storing the file identification data identifying the file in the replay log structure without storing the file payload data segment comprises storing a name of the file and a size of the file payload data segment of the file in the replay log structure. 
     
     
       4. The method of  claim 1 , wherein a first non-payload data segment of the plurality of non-payload data segments comprises header data associated with the file. 
     
     
       5. The method of  claim 4 , wherein a second non-payload data segment of the plurality of non-payload data segments comprises padding data located between an end of the file payload data segment and a next block boundary of the tar archive. 
     
     
       6. The method of  claim 5 , wherein a third non-payload data segment of the plurality of non-payload data segments comprises end-of-archive data located after a last file in the tar archive. 
     
     
       7. The method of  claim 6 , wherein the file payload data segment comprises contents of the file. 
     
     
       8. The method of  claim 1 , wherein the tar archive is organized in 512-byte blocks. 
     
     
       9. The method of  claim 1 , wherein accessing the tar archive comprises receiving a streamed tar archive. 
     
     
       10. The method of  claim 1 , wherein accessing the tar archive comprises reading the tar archive from a storage device. 
     
     
       11. The method of  claim 1 , wherein storing the plurality of non-payload data segments in the replay log structure comprises storing the plurality of non-payload data segments in the replay log structure in a same sequence as the plurality of non-payload data segments exist in the tar archive. 
     
     
       12. The method of  claim 1 , further comprising:
 receiving file payload data location information and replay log location information, and wherein accessing the replay log structure comprises accessing the replay log structure based on the replay log location information, and wherein accessing the file payload data segment of the file based on the file identification data comprises accessing the file payload data segment of the file based on the file identification data and on the file payload data location information. 
 
     
     
       13. The method of  claim 1 , wherein sending the plurality of non-payload data segments from the replay log structure in the same sequence as the plurality of non-payload data segments is arranged in the replay log structure comprises writing the plurality of non-payload data segments from the replay log structure in the same sequence as the plurality of non-payload data segments is arranged in the replay log structure to a storage device. 
     
     
       14. The method of  claim 1 , wherein sending the plurality of non-payload data segments from the replay log structure in the same sequence as the plurality of non-payload data segments is arranged in the replay log structure comprises streaming the plurality of non-payload data segments from the replay log structure in the same sequence as the plurality of non-payload data segments is arranged in the replay log structure to a downstream receiver. 
     
     
       15. The method of  claim 1 , further comprising:
 retrieving, from the replay log structure, the payload data validation value associated with the file; 
 generating, based on the file payload data segment, a new payload data validation value; and 
 determining that the payload data validation value matches the new payload data validation value. 
 
     
     
       16. A computing device, comprising:
 a memory; 
 a processing device coupled to the memory to: 
 access a tar archive comprising a file payload data segment and a plurality of non-payload data segments; 
 identify the plurality of non-payload data segments in the tar archive; 
 store the plurality of non-payload data segments in a replay log structure; 
 identify the file payload data segment of a file in the tar archive; 
 store file identification data identifying the file in the replay log structure, wherein the file payload data segment is not stored in the replay log structure; 
 generate a payload data validation value based on the file payload data segment of the file; and 
 store the payload data validation value in the replay log structure; and 
 generate a reassembled tar archive by: 
 access the file payload data segment of the file based on the file identification data;
 send the plurality of non-payload data segments from the replay log structure in a same sequence as the plurality of non-payload data segments are arranged in the replay log structure; and 
 send the file payload data segment of the file in a same position with respect to the plurality of non-payload data segments as in the tar archive. 
 
 
     
     
       17. A method, comprising:
 accessing a tar archive; 
 identifying a plurality of non-payload data segments in the tar archive interspersed with a plurality of file payload data segments, each file payload data segment comprising contents of a corresponding file stored in the tar archive; 
 storing the plurality of non-payload data segments in a replay log structure in a same sequential order as the plurality of non-payload data segments occurs in the tar archive; 
 storing file identification information for each respective file payload data segment that identifies the file corresponding to the respective file payload data segment in the replay log structure, wherein the plurality of file payload data segments is not stored in the replay log structure; 
 generating, for each respective file payload data segment of the plurality of file payload data segments, a payload data validation value based on the respective file payload data segment; 
 storing each payload data validation value in the replay log structure; and 
 generating a reassembled tar archive by:
 accessing the file payload data segment of the file based on the file identification data;
 sending the plurality of non-payload data segments from the replay log structure in a same sequence as the plurality of non-payload data segments are arranged in the replay log structure; and 
 sending the file payload data segment of the file in a same position with respect to the plurality of non-payload data segments as in the tar archive.